Green tea is a type of tea made solely with the leaves of Camellia sinensis that has undergone minimal oxidation during processing. Green tea originates from China and has become associated with many cultures in Asia from Japan to the Middle East. Recently, it has become more widespread in the West, where black tea is traditionally consumed. Many varieties of green tea have been created in countries where it is grown. These varieties can differ substantially due to variable growing conditions, processing and harvesting time.
Over the last few decades, green tea has been subjected to many scientific and medical studies to determine the extent of its long-purported health benefits, with some evidence suggesting regular green tea drinkers may have a lower risk of heart disease and developing certain types of cancer. Green tea has also been claimed useful for weight loss management.
Chinese and Japanese Green teas differ in processing, therefore are different in taste. The Chinese stir fry, roast, semi-roast and semi-fry, solar dry and steam, while the Japanese teas are only steamed and dried.
Potential Effects of Green tea on Health
Green tea consumption is reportedly associated with various health-promoting properties. For example, it has been shown to promote fat oxidation in humans at rest and to prevent obesity and improve insulin sensitivity in mice.
In a study performed at Birmingham (UK) University, it was shown that average fat oxidation rates were 17% higher after ingestion of Green Tea Extract than after ingestion of a placebo. Similarly, the contribution of fat oxidation to total energy expenditure was also significantly higher by a similar percentage following ingestion of Green Tea Extract. This implies that the ingestion of Green Tea Extract can not only increase fat oxidation during moderately intensive exercise but also improve insulin sensitivity and glucose tolerance in healthy young men.